Thyroid hormones are substances naturally made by the body and are important to many of your body's basic functions such as breathing and brain function. We are investigating whether or not these hormones are at lower levels in critically ill children which could lead to further health problems. We hope to get a better understanding of hormone levels and their effects on critically ill children to better help other children in the future.

Critically ill children with more severe thyroid hormone deficiencies will have greater severity of illness, intensity of therapeutic intervention, organ dysfunction, and increased morbidity and mortality. [ Time Frame: When study is completed. ] [ Designated as safety issue: No ]

Critically ill children requiring vasoactive infusions and/or mechanical ventilation are a population in the ICU that has thyroid hormone pertubation and significant morbidity and mortality. [ Time Frame: At completion of study ] [ Designated as safety issue: No ]

Patients who are receiving vasoactive medications and/or are mechanically ventilated.

Other: Blood draws

17 mls of blood will be drawn over a 5 day period from either a central venous catheter/arterial line or with scheduled phlebotomy. The following labs will be run tT3, fT3, rT#, tT4, fT4, TSH, and tyrosine.

Patient with known or presumed pre-existing thyroid disease will be excluded

Patients who receive thyroid supplementation will be excluded

Patients with known or presumed hypothalamic and/or pituitary dysfunction that have thyroid hormone concentration abnormalities not related to an acute illness.

Patients who are intubated for airway protection only.

Patients intubated for neuromuscular disease

Pregnant patients.

Patients receiving amiodarone supplementation

Patients who received blood product transfusions equaling more than 1/2 of their blood volume.

Contacts and Locations

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study.
To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below.
For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00664079